here I briefly explain the issue with time. Well, classical physics suggests a particular direction for time, i.e, everyday is distinguishable from yesterday. If you start a movie from one side to the other, it is distinguishable from playing it backward. However, the governing laws of nature are invariant in time. Additionally, Einstein theory of relativity, merged the nature of space and time together. So, spatial dimension the same as time dimension (we know that space does not have an intrinsic direction as time has, right!). Anyway, this distinction between (current) governing laws of physics and our natural world (at large scale) inspired a lot of discussions to better understand the nature of time. one of these ideas put forth by Lee Smolin which you can briefly hear in this podcast. He usually writes a concise and readable books and I am pretty sure his new book will be the same (in case you are interested. )